<!DOCTYPE html>
<html>
<head>
<style>
.abc {
  display: flex;
  flex-direction: column;
  flex-direction: column-reverse;
  flex-direction:  row;
  flex-direction:  row-reverse;
  background-color: DodgerBlue;
}

.abc > div {
  background-color: #f1f1f1;
  width: 100px;
  margin: 10px;
  text-align: center;
  line-height: 75px;
  font-size: 30px;
}
</style>
</head>
<body>
<h1>flex-direction 属性</h1>

<p>"flex-direction: column;" 垂直堆叠弹性项目（从上到下）：</p>

<div class="abc">
  <div>1</div>
  <div>2</div>
  <div>3</div>  
</div>

</body>
</html>
